Tune the instrument
you think with.
Sessions built on how the auditory system actually behaves — beats carried where the nerves can still track them, targeted at a named brainwave band, and drawn in real time as 3D cymatics. Any tone from 1 to 20,000 Hz.
No account needed · Headphones strongly recommended
Four measurements that decide what sound can and cannot do to you. Everything below follows from them.
10⁻¹¹ m
Eardrum travel
Movement at the quietest audible sound — a shorter distance than the width of a hydrogen atom.
~10 µs
Interaural resolution
The timing gap between your two ears that the brainstem can still measure. Binaural beats run on this circuit.
1839
First described
Heinrich Wilhelm Dove documents the binaural beat. It stays a curiosity for another 134 years.
1.5 kHz
The hard ceiling
Above this carrier, auditory nerves stop firing in step with the wave and the beat simply never forms.
Hearing is stranger
than the brochure version.
None of this is metaphor. Each one is a measured, replicated finding from the auditory sciences — and each one is more interesting than the claims usually made in their place.
Your ears emit sound
The cochlea does not just receive — outer hair cells actively amplify quiet sound, and that amplifier leaks. A healthy ear produces faint tones a microphone in the ear canal can record. Newborn hearing screening works by playing a click and listening for the echo that comes back.
Otoacoustic emissions · Kemp, 1978You hear notes that are not there
Strip the lowest harmonic out of a musical tone and the pitch you perceive does not move. The brain reconstructs the fundamental from the spacing of what remains. It is why a phone speaker physically incapable of reproducing a bass line still lets you hear one.
The missing fundamental · Seebeck, 1841The brain adjusts its own microphone
A bundle of nerve fibres runs the wrong way — down from the brainstem into the cochlea. It lets the brain turn the ear's own amplifier down, sharpening a voice out of background noise. Hearing is an outgoing instruction as much as an incoming signal.
Medial olivocochlear efferentsDeep bass is partly a balance sense
The saccule is a vestibular organ, part of the apparatus that tells you which way is up. It also keeps measurable sensitivity to low frequencies at high levels. Some of what a heavy bass note does to you is not being heard at all.
Todd & Cody, acoustic vestibular responseForgotten for 134 years
Dove's 1839 binaural beat sat unexamined until Gerald Oster revived it in Scientific American in 1973. His interest was diagnostic, not therapeutic: a person who cannot perceive the beat may have a neurological difference worth investigating.
Oster, "Auditory Beats in the Brain", 197340 Hz is the auditory system's favourite rate
Drive the ear with a rhythm and the brain follows it best at around 40 Hz — the response peaks there and falls away either side. It is reliable enough to be used clinically to test hearing in patients who cannot tell you what they hear.
40 Hz auditory steady-state response · Galambos, 1981Everything explained on this page is drawn from published auditory science — but not every claim in this field is equally well supported, and it is worth seeing which is which.
hzaura is built for calm, focus and curiosity. It is not a medical device and not a treatment. If you have epilepsy or a seizure disorder, talk to a doctor before using rhythmic audio.
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